Log Into OSCER Systems

Creating a VS Code Server task on the login nodes can consume a significant amount of memory. If multiple users do this. This could potentially CRASH the login nodes, thus preventing all 1000+ OSCER users from logging in!

If you need help with the steps below, you're welcome to join OSCER's Zoom help sessions, held every Thursday from 1:00 PM to 3:00 PM and Friday 1:00 PM to 2:00 PM.

For security reasons, access to OSCER resource is availably via Secure Shell only.

• Windows
  • (A) MobaXterm
  • (B) PuTTY
• MacOS
• Linux

1. Download and Install MobaXterm

• Go to the MobaXterm Home Edition download page: https://mobaxterm.mobatek.net/download-home-edition.html. We recommend using the Portable Edition, as it does not require installation. Simply download the compressed file and extract it to a folder of your choice.

2. Run MobaXterm

• After extracting the downloaded ZIP file, locate the MobaXterm executable and double-click it to launch the program. At the time of writing, the latest version is 26.1, so the file name may appear as MobaXterm_Personal_26.1.exe. The exact name may vary depending on the version you download.

• The first time you run MobaXterm, a Windows Firewall may appear. You can safely ignore this by clicking Cancel.
  

3. Create a SSH Session

• In the top left corner of MobaXterm user interface, click on Session icon.
  

• Select SSH and enter the required connection details:
  • In the Remote host field, type sooner.oscer.ou.edu
  • Enter your OSCER username in the Username field.
  • Set Port to 22.
• Click OK to start the session.

• The first time you connect to OSCER, you will need to trust the connection by clicking the Accept button in the popup window.
  

• When prompted, enter your OSCER account password. Note: Nothing will appear as you type your password. This is normal behavior for SSH.
  

• If you see an Acces Denied message and are prompted to re-enter your password, your username or password may be incorrect. Try again carefully.
• If you forgot your password, you can find instructions to reset it here: https://account.oscer.ou.edu/
• If you forgot your OSCER username and/or email used to register for your OSCER account, please contact OSCER support at support@oscer.ou.edu

• By default, MobaXterm may ask if you want to save your password for future sessions. For security reasons, we do not recommend enabling this feature. 

• However, If you choose to save your password, you will need to create a MobaXterm master password, which is different from your OSCER account password.

• The image below is how MobaXterm looks like after you successfully logged in. The left panel is a mini file browser based on SFTP (Secure File Transfer Protocol) connection, showing the file and directory structure of your home directory right after you log in. The right side is your terminal, where you would type different commands to set up your work environment, compile your code, and/or run your favorite Linux software.
  

4. Close a SSH Session

• When you finish working with OSCER, you can either close MobaXterm or just the current session "tab".
• MobaXterm will ask you to confirm that you want to close the SSH session. Click Yes to confirm.

• MobaXterm automatically saves your SSH session configuration. The next time you want to reconnect to OSCER, simply double-click the saved session in the left panel.

1. Downloading and Install PuTTY

• Point your browser to the PuTTY download page:
  http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html
  
  
• On the "PuTTY Download Page," in the section titled "Binaries," under "For Windows on Intel x86," right click on the first link putty.exe, and from the menu select "Save Link As" (or something similar).
  
  
• Save putty.exe to your Windows desktop. The icon will look like two little PCs and a yellow lightning bolt.
   

2. Running PuTTY to Log In to an OSCER Computer

• Double click the PuTTY icon to open the PuTTY Configuration window.

• In the left-hand menu, navigate to Terminal -> Keyboard, then update the following settings
  
  • Under The Backspace key, set the value to Control-H
  • Under The Function keys and keypad, select Xterm R6    

• In the PuTTY Configuration window, select Window from the left-hand menu. This opens the section labeled Options controlling PuTTY's window. Under Set the size of the window, you may chose any number of rows (40 is recommended), but set the number of columns to exactly 80.

• Do not resize the PuTTY window using the mouse, and do not use the maximize button in the top-right corner of the window.

• In the PuTTY Configuration window, navigate to Connection -> SSH -> X11. Under Options controlling SSH X11 forwarding, enable X11 forwarding.

• Note: X11 (X-Windows) forwarding will only work if your Windows computer has an X-Windows emulator installed (such as Xming). If you do not have an X-Windows emulator, you can skip this step.

• In the PuTTY Configuration window, select Session from the left-hand menu. This opens the Basic options for your PuTTY session section, where you should complete the following:
  • In Host Name (or IP address), enter the full name of the system you are connecting to (e.g., sooner..oscer.ou.edu). (Click here for a list of all OSCER login nodes.)
  • Under Connection type, select SSH.
  • To save the session for future use, go to Load, save or delete a stored session, enter a name for the session (for example, sooner.oscer.ou.edu), then click Save.

• At the bottom-right of the PuTTY Configuration window, click Open.
• If a PuTTY Security Alert appears, select Yes to continue.
• When prompted to login as, enter your username and press Enter.
• When prompted for your password, type it and press Enter. Note that nothing will appear on the screen as you type your password. This is normal behavior in Unix systems.

Mac OS X includes a built-in Terminal application that can be used to SSH into OSCER systems. Follow the steps below to connect from a Mac:

1. Open your hard drive.
2. Navigate to the Applications folder.
3. Open the Utilities folder.
4. Launch the Terminal application.
5. Once the termianl window opens, you will see a Unix command prompt. At the prompt, enter:
ssh username@machinename
   Replace username with your OSCER username. For OSCER systems, the machine name is: sooner.oscer.ou.edu
   (Click here for a list of all OSCER login nodes)
   
6. You may be prompted to confirm the connection with a yes/no questions: if so, type: yes
7. You'll then be asked for your password. Enter it and press Enter. Note that nothing will appear on the screen as you type your password. This is normal behavior on macOS and Linux systems.

Most Unix systems already include SSH, so you can use it directly from the command line. Simply follow the same process described for macOS, beginning with Step 5

Next: Linux Basics